mongo sets the value of id property long:

12 bytes:

• 4 bytes: timestamp →
  • this is the reason we don’t have to add created at attribute, because it is already there in id
  • To sort by time , we can just sort them using the id
• 3 bytes: machine identifier
• 2 bytes: process identifier
• 3 bytes: counter
  • If everything is save, multiple document with same, timestamp, same machine, and same process , the counter will make them different

1 byte = 8 bits
2 ^ 8 = 256 
2 ^ 24 = 16M

This id is generated by MongoDB driver

Driver → mongo db

mongoose is an abstraction over mongo db driver

To get time stamp from id :

id.getTimeStamp();

Validate id:

const isValid = mongoose.Types.ObjectId.isValid(id);